In environments of excessive sound levels, the human auditory system suffers damage. These environments include, without limitation, combat settings for the military and civilian authorities, aviation, emergency rescue and healthcare, construction, manufacturing, mining, forestry, hunting, entertainment and others. Often the excessive sound levels are intermittent bursts whose exact timing cannot be anticipated. In such settings, attenuating sound levels is not enough because there is an equivalent need for communication and information gathering through the auditory system on account of the needs of safety and job performance. Communications, information gathering and safety would be much improved if attenuation were coupled with effective means to block out sounds temporarily when ambient levels are dangerous to the auditory system. Likewise, these ends would be served best if the sounds allowed through to the auditory system were of the highest fidelity possible. There is also a need for an effective apparatus and method for reconnaissance providing heightened sensitivity to low level ambient sounds.
The present invention should be used in any environment where electrically augmented communication or auditory detection is required. For example, soldiers in combat must use all of their senses to survive and perform on the modern battlefield. Their hearing must be protected from damage from hazardous impact and sustained noise, (i.e. small arms firing, artillery, aircraft and armor noise), without compromising their ability to hear and communicate in these environments. Hearing is often essential to detect, locate and recognize the enemy. As well, soldiers must understand ambient sounds within their immediate environment and communicate between themselves both on a face-to-face basis, and via radio in secure modes during mission operations. Operational contingencies, missions and environments, such as night reconnaissance and operations, Chemical, Biological and Nuclear (CBN) defense modes, or smoke, dust and haze during movement on the battlefield confound the soldier's ability to perform these tasks. Communication would be undiminished in personnel wearing full body protective clothing (e.g. Chemical Protective Ensembles, Whole-body Thermal Protective Suits) when the invention is integrated into the ensemble. Emergency and rescue personnel, firefighters, law enforcement, interdiction, counter-terror and SWAT teams, recreational shooters, hunters as well as heavy industry and construction workers would all benefit from the face to face and electronic communication augmentation attributes of this invention, as well as the high level of hearing protection it provides.
There have been efforts to attenuate excessive sounds with barrier devices, and there have been efforts to filter out or block excessive sound levels with electronic systems. There remains a need, however, for devices and methods which allow sufficient fidelity for the ambient and necessary sounds of speech and the local environment, and which also provide superior protection by attenuating ambient sounds and then allowing only those sounds through the electronic system which do not exceed levels unsafe to the auditory system.